1. Field of the Invention
The present invention relates to a keyswitch device having a keytop, which is supported so as to be slidably guided to both upward and downward directions through a support member arranged on a keyholder plate. More particularly, the invention relates to a keyswitch device with good operational feeling of the keytop, in which assembly of the support member, the keyholder plate, the support member and the keytop can be easily done.
2. Description of Related Art
Conventionally, various kinds of keyswitch devices have already been proposed. In such keyswitch devices, in general, that a keystem formed from a back surface of a keytop is slidably guided to upward and downward directions through a key guiding portion formed on a keyholder plate.
In the keyswitch devices having such construction, operational feeling of the keytop is improved when the key guiding portion of the keyholder plate, through which the keystem is slidably guided, is lengthened. Such a lengthened key guiding portion, on the contrary, cannot be adopted for keyboards which recently have a tendency to be thinned. On the other hand, there is the dilemma that operational feeling of the keytop is deteriorated because the keystem is inclinedly guided relatively to the key guiding portion while contacting with each other if the key guiding portion is shortened in order to correspond to thinning tendency of the keyboards.
In order to dissolve the above dilemma existing in the conventional keyswitch devices, applicant of the present invention proposed, in U.S. Pat. Nos. 5,278,372, and 5,280,147, a keyswitch device capable of corresponding to thinning tendency of the keyboards and accomplishing good operational feeling of the keytop by removing both the keystem and the key guiding portion therefrom. Such keyswitch device is shown in FIGS. 9 to 11. Construction of the keyswitch device will be summarized hereinafter.
In FIG. 9, a resinous keytop 1 has two holding portions 2 and 3 which are formed from back surface of the keytop 1. Here, each of the holding portions 2 and 3 exists in a pair, respectively. And an engaging hole 4 is formed in the holding portion 2 and an engaging slot 5 is formed in the holding portion 3. Further, a resinous holder plate 25 on which two holding portions 26, 27 are formed, is arranged under the keytop 1. Here, each of the holding portions 26 and 27 exists in a pair, respectively. In the holding portion 26, an engaging slot 28 is formed and, in the holding portion 27, an engaging hole 29 is formed. Between the keytop 1 and the holder plate 25, a guide support member 6 is arranged. The guide support member 6 comprises two hinge members 7 and 8. Both the hinge members 7 and 8 are crossedly supported at a supporting part A, as mentioned hereinafter. The hinge member 7 has a pair of engaging pins 13 and 14 at one end thereof and a pair of another engaging pins 15 and 16 at the other end thereof. Each of the engaging pins 13 and 14 is engaged into the engaging hole 4 and each of the engaging pins 15 and 16 is engaged into the engaging slot 28. And the hinge member 8 has a pair of engaging pins 21 and 22 at one end thereof and a pair of engaging pins 23 and 24 at the other end thereof. Each of the engaging pins 21 and 22 is engaged into the engaging hole 29 and each of the engaging pins 23 and 24 is engaged into the engaging slot 5. According to the above construction of the keyswitch device, the keytop 1 is guided to both upward and downward directions through the guide support member 6.
The supporting part A, where the hinge member 7 and the hinge member 8 are crossedly supported with each other, is put on top of a rubber spring 31 mounted on a flexible circuit board 30 installed on a supporting plate 32. Thus, when the keytop 1 is depressed, the supporting part A depresses the rubber spring 31 so as to be buckled for switching action.
Here, as shown in FIG. 10, the hinge member 7 has a base part 9 at both ends of which two base end portions 10 and 11 are formed into one body. From one side surface of central position of the base part 9, a shaft 12 which is supported into a shaft hole 20 (later mentioned) of the hinge member 8 is extended. And the engaging pins 13 and 14 are extended from each of side surfaces of extending portions 10A formed from both sides of the base end portion 10. Each of the engaging pins 13, 14 is engaged into the engaging hole 4 formed in the holding portion 2 of the keytop 1. Further, the base end portion 11 is shaped like a U, as shown in FIG. 10, and the engaging pins 15 and 16 are extended from each of side surfaces of extending portions 11A formed from both sides of the base end portion 11. Each of the engaging pins 15, 16 is engaged into the engaging slot 28 formed in the holding portion 26 of the holder plate 25 so that each of the engaging pins 15, 16 becomes slidable in the engaging slot 28.
And as shown in FIG. 11, the hinge member 8 has a base part 17 at both ends of which two base end portions 18 and 19 are formed into one body. In the central position of the base part 17, a shaft hole 20, into which the shaft 12 formed in the base part 9 of the hinge member 7 is inserted, is bored. The base end portion 18 is shaped like a U, as shown in FIG. 11, and the engaging pins 21 and 22 are extended from each of side surfaces of extending portions 18A formed from both sides of the base end portion 18. Each of the engaging pins 21, 22 is engaged into the engaging hole formed in the holding portion 27 of the holder plate 25. Further, the engaging pins 23 and 24 are extended from each of side surfaces of extending portions 19A formed from both sides of the base end portion 19. Each of the engaging pins 23, 24 is engaged into the engaging slot 5 formed in the holding portion 3 of the keytop 1 so that each of the engaging pins 23, 24 becomes slidable in the engaging slot 5.
As mentioned above, the guide support member 6 is constructed so that the shaft 12 extended from the base part 9 of the hinge member 7 is inserted into the shaft hole 20 bored in the base part 17 of the hinge member 8, therefore each of both the hinge members 7, 8 becomes rotatable with each other through supporting part A constructed from both the shaft 12 of the hinge member 7 and the shaft hole 20 of the hinge member 8.
According to the keyswitch device constructed above, a keyswitch device can be constructed with good operational feeling of the keytop 1, which is able to correspond to thinning tendency of keyboards.
However, there is a problem in the conventional keyswitch device mentioned above that assembly of not only the holder plate 25 and the guide support member 6 including the hinge member 7 and the hinge member 8 but also the guide support member 6 and the keytop 1 cannot be easily or simply done.
That is to say, when the keyswitch device is assembled, at first, the guide support member 6 is assembled by crossedly combining the hinge member 7 and the hinge member 8 through the shaft 12 and the shaft hole 20. Thereafter, the engaging pins 21, 22 extended from the base part 18 of the hinge member 8 are pressed into the engaging hole 29 of the holding portion 27 formed on the holder plate 25. At that time, though pressing of the engaging pins 21, 22 into the engaging hole 29 is conducted by utilizing resinous elasticity of the extending portions 18A and the engaging pins 21, 22, it is difficult to correctly position the engaging pins 21, 22 in the engaging hole 29. Therefore, pressing action of the engaging pins 21, 22 into the engaging hole 29 is apt to be unstable and thus, such pressing action is considerably troublesome.
Thereafter, the engaging pins 15, 16 extended from the base end portion 11 of the hinge member 7 are pressed into the engaging slot 28 of the holding portion 26. In this case, since pressing action of the engaging pins 15, 16 into the engaging slot 28 is conducted by utilizing resinous elasticity of the extending portions 11A and the engaging pins 15, 16, pressing action is considerably troublesome similar to pressing action of the engaging pins 21, 22.
After finishing the connecting action between the hinge members 7, 8 and the holding portions 26, 27 of the holder plate 25, both the pressing action of the engaging pins 13, 14 in the hinge member 7 into the engaging hole 4 of the holding portion 2 and the pressing action of the engaging pins 23, 24 in the hinge member 8 into the engaging slot 5 of the holding portion 3 are conducted. Since the thus pressing actions are also conducted by utilizing resinous elasticity of the engaging pins 13, 14, 23, 24 and the holding portions 2, 3, such pressing actions become considerably troublesome, similar to the above.
As mentioned above, in the above constructed conventional keyswitch device, there is a problem that it is necessary to conduct the troublesome pressing actions over assembling of the keyswitch device, since connecting of the hinge members 7, 8 of the guide support member 6 to both the holder plate 25 and the keytop 1 is realized by utilizing resinous elasticity. Further, the engaging pins 13 to 24 are necessary to be engaged into the engaging holes 4, 29 and the engaging slots 5, 28 while correctly positioning thereof.